Screen for paper-making machines.



No. 628,234. Patented July 4, I899.

' B. SMITH.

SCREEN FUR PAPER MAKING MACHINES.

(Application filed June 30, 1898.)

(No Model.)

THE Noam P-TERS cu. vm'mumou wuumutcn. n. c.

UNITED STATES PATENT OFFICE;

RICHARD SMITH, 0F SHERBROOK, CANADA.

SCREEN FOR PAPER-MAKING MACHINES.

SPECIFICATION. forming part of Letters Patent No.'6 28,234., dated July 4., 1899.

Application filed June 30, 1898. Serial No. 684,903. (No model.)

To all whom it may concern:

Be it known that I, RICHARD SMITH, residing at Sherbrook, in the county of Sherbrook, Province of Quebec, Canada, have invented certain new and useful Improvements in Screening Mechanism for Paper-Making Hachines, of which the following is a specification. 1

This invention relates to screening-machines having a diaphragm arranged below the screen and provided with means for vibrating said diaphragm, so as to produce an alternate suction and blast through the slits;

The said invention consists, chiefly, in certain improvements in the construction and combination of the said strainer-plates and their frame whereby said plates may easily be inserted horizontally in position and with drawn therefrom, they being held securely in said frame without any risk of accidental displacement or injury. I

The said invention also consists in certain improvements in the spring which acts on the diaphragm whereby it is double instead of single and will continue to be operative in case either spring happens to break.

The drawings accompanying this specification represent, in Figure 1, a part side eleva tion part vertical section of my improved screen; in Fig. 2, a plan, and in Fig. 3 a vertical section, of one end of such screen. Fig. 4 is a plan, Fig. 5 an end view, and Fig. 6 an edge view,-of the screen-plate.

7 shown at 5, 850., and the slots of the same at 6 6 6, &c. The side edges 5 5 of each screenplate are beveled, and these beveled edges are adapted to enter correspondingly-formed grooves 8 in'opposite sides of the screenframe, the dovetailed joint thus produced ef- Fig. .7 is a. face View, and Fig. 8 a vertical section, of the fectually securing the plate in place against any loosening in a vertical direction and preventing any fracture of such plate, which would otherwise occur at the points of the screw-heads. The inner or rear edge of the screen-plate may also be beveled to engage a groove in the rear bar of the screen-frame.

The side edges of the screen are slightly wedge-shaped in the direction of their length, as shown at 8 in Fig. 6 of the drawings, and the grooves 8 in the screen-frame are of corresponding shape. An equivalent of the bev eled joint between the screen frame and plate would be a shelf-groove and tongue, as shown in Fig. 9 of the drawings, which represents a section of the parts. hen the plate is driven home, the wedge-joint thus formed prevents under all ordinary circumstances any longitudinal loosening of the plate; but to provide extreme protection against such loosening I employa locking device, which in the present instance is composed as follows:

9 represents a latch-plate of a length approximating the width of the screen-plate,

this latch-plate being hinged at its lower edge tothe front side bar of the screen-frame and below the opening in the latter, through :which the screen-plate is inserted, the said hinge being shown at 10. Tolock the latchplate in its closed position, Iemploy two horizontal lugs 13 13, formed upon or secured to the bar 3 of the screen-frame and having each a vertical slot 14 to receive. a wedge 15. The upper part of the latch-plate has slots 16 1,6 to embrace or inclose the lugs 13. When in a closed or locked state, the latch-plate is prevented from dropping by the wedges. To release said latch-plate, the wedgesare removed and the plate lowered, thus exposing the screen-plate and permitting of removal of the latter.

The cam ot' the mechanism for vibrating the diaphragm is shown at 18 and the hardepending from the bottom of a disk or plate 24, attached to the under side ofthe flexible diaphragm 23, arranged under the screen-frame and operating with such cam, at 19, these features being of the construction now in general use. The wooden spring proper for maintaining the lower end of the bar 19 in close contact-with the cam 18 is shown at 20 as confined at its outer end to one of the housings l in the usual manner. Such springs are cheap and preferred for other reasons in this class of machines; but as they are easily broken it becomes desirable to add another spring, which will act instead of the wooden one when it breaks and increase resiliency when both act together. i

The auxiliary or secondary spring, which constitutes one of the features of my present invention, is shown at 21 as disposed below the first, and, like the latter, is confined at its outer end to the housing 1, this secondary spring being connected with the spring proper by bolts, as shown in the drawings, or in any suitable manner which permits the two to act in unison and exert a common stress upon the bar 19,.

Vhat I claim is as follows:

1. In combination with a screen-frame having internal, transverse grooves and openings at the ends thereof to permit the end wise with drawal of the screen-plates, a series of screenplates and means for holding them in the said grooves, any one of the said plates being removable horizontally and longitudinally through the sides of said frame without displacing any of the others substantially as set forth.

2. In combination with a screen-frame, a series of horizontally-rem ovable screen-plates or strainer-plates, each plate being beveled laterally and wedge form longitudinally, and the said frame having grooves of corresponding shape to receive the said edges, substantially as set forth.

3. A screen-frame having an opening and a screen-plate received in said opening and removable through the same, in combination with a latch-plate hinged to the said frame and a locking device for the said plate, the end of the frame being grooved in the inner side to receive the end of the said plate substantially as set forth.

t. In combination with a screen-frame and a diaphragm arranged below the same, the jolting mechanism acting on the said diaphragnl and a compound spring acting on the said mechanism, consisting of the wooden spring ordinarily used for such purposes and a metallic spring connected thereto and cooperating therewith, such additional spring being adapted and arranged to continue the resilient action on and with the said mechanism after the said wooden spring has been broken, substantially as set forth.

In testimony whereof I affix my signature in presence of two Witnesses.

RICHARD SMITH. 

